1. Field of the Invention
The present invention relates to telecommunication systems and, in particular, is directed to a method and system for controlling subscriber access to services accessed through a telecommunication system using short messages.
2. Description of Related Art
Mobile communication networks, such as digital GSM (Global System for Mobile Communications) networks, have become extremely popular throughout a large part of the world. The primary advantage presented by mobile communication networks, as compared to traditional fixed telephone networks, is the air or wireless interface provided between the subscriber's terminal device and the physical wired network, which wireless interface enables wide-ranging subscriber mobility.
Since their introduction, digital mobile networks have provided to their subscribers the ability to use and access a variety of services including the so-called short message service or SMS. In the short message service a subscriber or user of a mobile station has the ability to send a short text message of up to 160 characters from the user's mobile station to, by way of example, another user of a respective mobile station who has a terminal device capable of receiving the short message. The short message is transmitted from the mobile station via a wireless interface separate from or outside of the speech-transmitting time slots, there enabling a user to receive short messages at the same time that the user is already engaged in an ongoing voice call with a different party.
To date, short messages have become very popular among telecommunication system subscribers, and system operators have developed and implemented an unusually large number of short messaging services and other services that are accessible or usable via short messages for additional charges. This has in practice meant that a certain portion of the available numerical address space on the system has been allocated for these services. Technically this means that separate analyses are carried out in the short message service center for these various allocated numbers; based on these analyses, short messages sent by subscribers to those numbers are further forwarded or transmitted to the appropriate locations, such as service providers or application providers.
The short message service has typically either been activated for a particular subscriber or it has not been activated for that subscriber. As currently implemented the systems for transmission of short messages do not permit the blocking of short message service messages or requests based on the B-subscriber (i.e. the intended recipient) number or based on specific or otherwise predetermined or specified search words or terms that may be contained in the short message text. This has limited the versatility of short messaging services and has prevented service providers and system operators from providing or fully implementing some services that subscribers might otherwise use or access via short messages.